Minggu, 23 Juni 2013

What is the average wavelength of light that is filtered in a camcorder?

Q. Up to what wavelength of light does a camcorder filter out?

Also, does infrared light between 1350-1650nm have harmful effects on humans?

If so, what side effects are experienced and what can be done to remedy the problem?

Also, does anyone know where I can get infrared producing LEDs?

Thanks for your time.

A. Whether or not a particular camcorder a) includes an IR filter (and how effective it is) or b) has a sensor with good sensitivity in the IR range, is often not to be found in the camera's specs, but can be readily determined by using the IR remote mentioned in the above post.

In a darkened room, blink an IR remote at your camera from a distance of about 3 feet. View the resulting video. If you see a fairly bright white flash, your recorder isn't filtering much of the IR, and is reasonably sensitive to it, and you can use IR illumination for "dark" recording.

Typically, there's nothing you can do to either improve the sensitivity of the sensor or to remove the filter (often coated directly onto a lens element or CCD / CMOS sensor), so whatever a given camera does out of the box is pretty much what you're stuck with. Some are far more capable in the IR range than others.

IR illuminators for CCD surveillance cameras and the like can be found all over the web in all sorts of configurations. We've tested this one (it comes in several wavelengths and with several lens angles if you get it directly from the mfgr) and had good success with it -- very bright (although they run a bit hot):

http://www.smarthome.com/7698ir4.html

You'll find these illuminators produce a great deal more light than the LED variety, but the LED flavor can also be found at sites like this one:

http://www.thespystore.com/infraredilluminator.htm

The LEDs are available from just about any company that manufactures LEDs of any type and can be picked up readily at outfits like Mouser, DigiKey, etc. for a couple of bucks each.

http://www.mouser.com/search/ProductDetail.aspx?R=LI521virtualkey61510000virtualkey889-LI521

It's really easier to buy the assembly rather than building one.

The IR won't hurt a thing. Think of it as heat (since that's the spectrum). You don't really need or want to go to 1350~1650nm for this project. You're MUCH, MUCH less likely to get the sensor in any normal camcorder to respond to wavelengths that low, and it's MUCH easier to get illuminators and/or LEDs in the 820nm~870nm range anyway. Stick with that range, and you'll be much happier.
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I purchased a camcorder from Photo Dynastey on line they have changed the price?
Q. I purchased a camcorder from Photo Dynasty for $999.99 with free shipping I purchased the elite package which covered a lot of assesories They wanted me to call before shippment which I did now they want $1299,99 for the package and if I cancel they will charge me $138.00 has anyone heard of a cancelation charge and can they legally do this.There web clearly states whats included in the package.

A. You probably thought you were getting a REALLY good deal, too...

http://www.complaintsboard.com/complaints/photo-dynasty-c81833.html

http://thoughts-of-dave.blogspot.com/2008/05/photodynastycom-negative-reviews-on.html

http://www.webtekconcepts.com/2008/05/05/photodynastycom-tells-spouse-of-deployed-soldier-war-is-an-excuse-after-bait-and-switch/

http://forums.cnet.com/5208-7593_102-0.html?forumID=58&threadID=110397&messageID=2774198

http://www.resellerratings.com/forum/merchant-discussion-shopping-advice/134840-warning-photo-dynasty-aka-shop-digital-direct.html

http://www.mightyfunk.com/2008/05/soniccameras-internet-fraud/

There are more... but you probably get the idea... good luck getting this resolved - I hope you don't get ripped off...

If it looks too good to be true, it probably is...





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